Brain Blood Circulation Affects Alzheimer’s Severity

Scientists in Singapore have suggested that Alzheimer’s disease patients should be treated according to whether they have cerebrovascular disease.

AsianScientist (Oct. 2, 2017) – In a study published in Brain, scientists in Singapore report that Alzheimer’s patients with and without co-occurring blood circulation problems in the brain may require different treatments.

The burden of dementia is increasing exponentially worldwide, especially in the Asia-Pacific, with an estimation that the number of dementia sufferers in the region will triple to 71 million people by 2050. In this same period, the number of dementia patients in Singapore is also projected to rise rapidly to 187,000.

Alzheimer’s disease is the most common form of dementia accounting for up to 60 percent of all cases. Moreover, Alzheimer’s disease co-presenting with cerebrovascular disease (CeVD), or blood circulation problems in the brain, accounts for nearly 20 percent of all dementia cases in Asia.

In this study, researchers at Singapore’s Duke-NUS Medical School (Duke-NUS) and the National University of Singapore Yong Loo Lin School of Medicine (NUS Medicine) analyzed a local cohort of 235 Singapore residents with prodromal (early stage) and clinical Alzheimer’s disease. They revealed that there are significant differences in functional connectivity and structural networks in the brains of patients with and without CeVD.

Specifically, only Alzheimer’s disease patients without CeVD exhibited reduced posterior default mode network functional connectivity, meaning that their resting-state brain activity was abnormal. In contrast, patients with the double burden of Alzheimer’s disease and CeVD showed much greater reduction of frontal executive control network functional connectivity, which impairs their ability to execute thoughts and tasks.

These different presentations suggest that there may need to be different clinical approaches in treating patients who only have Alzheimer’s disease, and those who either only have CeVD or have CeVD as well as Alzheimer’s disease.

“In light of the growing prevalence of Alzheimer’s disease and CeVD in Asia, and particularly in Singapore, our findings could form the basis for better patient management, disease monitoring and long term treatment planning,” said study senior author Assistant Professor Juan Helen Zhou of Duke-NUS.

“Although there is a growing awareness of Alzheimer’s disease and CeVD, the lack of well-defined criteria and treatment guidelines means that Alzheimer’s disease with CeVD is largely underdiagnosed,” added the study’s co-author, Associate Professor Christopher Chen of NUS Medicine.

“With this study, we demonstrated the combined effects of Alzheimer’s disease and CeVD on brain network degeneration, and further studies could shed more light into the clinical characteristics of these two important brain pathologies.”

The article can be found at: Chong et al. (2017) Influence of Cerebrovascular Disease on Brain Networks in Prodromal and Clinical Alzheimer’s Disease.


Source: Duke-NUS Medical School; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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